Borehole apparatus



June 30, 1959 H. B. BOLLER BOREHOLE APPARATUS Filed NOV. 23, 1955 HYDRAULIC PRESSU RE ...2... .r 42,... /w/v/ A ...,J. W... F w.. 2 l l INVENTOR.

HARRY B. BOLLER.

HIS ATTORNEY.

United` States Patent O noREHoLE APPARATUS Harry B. Boller, Alhambra, Calif., assignor, by mesne assignments, to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Application November l23, 1955, Serial No. 548,712

8 Claims. (Cl. 166-100) This invention relates to a borehole apparatus and, more particularly, pertains to a new and improved mechanical coupling system for connecting a wall-engaging member to a support adapted to be passed through a borehole drilled into the earth. While the invention has a wide variety of applications, it is ideally suited for use in association with sidewall formation-fluid-sampling apparatus of the type' disclosed in Patent No. 2,674,313, Chambers. For convenience, it will be described in this connection.

The fluid sampler disclosed in the patent to Chambers is provided with a pack-off shoe that is driven into engagement with the sidewall of a borehole at the depth of a formation to be sampled. This shoe is designed to seal a portion of the formation from the drilling liquid that usually iills the borehole and thus uid from the formation may ilow via an entry port in the shoe to a sample-retaining chamber. After a desired amount of fluid is obtained, the sample-retaining chamber is closed, the shoe is retracted and the apparatus is withdrawn from the borehole so that the sample may be measured and analyzed.

While the operation of this fluid sampler is highly satisfactory under the usual borehole conditions. in some instances a borehole under investigation may be so irregular in its diameter that a complete seal of the formation from the drilling liquid may not be obtained. Consequently, under some conditions it may not always be possible to obtain a fully representative sample of formation fluid.

It is, therefore, an object of the present invention to provide a new and improved mechanical coupling system for mechanically connecting a wall-engaging member with atsupport adapted to be passed through a borehole wherein fully reliable operation is obtainable not only under the usual borehole conditions but also in sections of a borehole in which the sidewall is etectively tilted relative to the longitudinal axis of the borehole.

Another object of the present invention is to provide a new and improved mechanical coupling system for connecting a pack-off shoe to a support adapted to be passed through a borehole featuring a better seal than heretofore possible between the formation to bev tested and the borehole fluid in a section of the borehole of non-uniform diameter.

Borehole apparatus in accordance with the present invention comprises a support adapted to be passed through a borehole and having a longitudinal axis. A wall-engaging member is carried by the support and is movable from a retracted position adjacent this support toward an active position in engagement with the sidewall of the borehole, and actuating means for the wallengaging member-is also carried by the support. The apparatus further comprises connections for mechanically coupling 4the support to the actuating means and for mechanically coupling the actuatingmeans to a wallengaging member, one of these connections has portions connected Yfor pivotal movement relative, to oney anotherl ICC 2 in a plane passing through the longitudinal axis thereby to permit tilting movement of the wall-engaging member with respect to this axis.

In a specific embodiment of the invention, the actuat ing means includes a pair of driven members spaced from one another in the direction of the longitudinal axis. These driven members are movable in respective directions transverse to the longitudinal axis. The aforesaid pivotal connection mechanically couples one of the driven members to a respective portion of the wall-engaging member and another pivotal connection mechanically couples the other of the driven members to another respective portion of the wall-engaging member.

According to another embodiment of the invention, a pivotal connection mechanically coupled the actuation means to the support.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which:

Fig. l is a Vperspective view of la sidewall fluid sampler incorporating a mechanical coupling system for connecting a pack-off shoe to the support embodying the present invention and illustrating one portion of an operating cycle for the sampler; v

Fig. 2 is a side view of a portion of the apparatus illustrated in Fig. l, drawn to an enlarged scale, and illustrating another portion of an operating cycle, certain parts thereof being shown in Out-away and in section to reveal various interior details;

Figs. 3 and 4 represent two operating conditions for a fluid sampler featuring another embodiment of the present invention; and

Fig. 5 is an enlarged view partly in section of one pivotal connection shown in Fig. 2.

In Fig. l of the drawing, the fluid sampler incorporating a preferred embodiment of the present invention is shown disposed in a borehole 1G traversing earth formation. 11, 12 and 13, and containing a drilling fluid 14 such as a water base or oil base mud. It is assumed that formation 12 is 'the one of interest from which a sample is to be obtained.

The fluid sampler comprises upper and lower pressure-resistant housing sections 15 and 16 connected together in longitudinally spaced relation by a pair of side rails 17 and 18 which are transversely spaced from one another. The device 15, 16 is suspended in the borehole 10 by a cable 19 which, in connection a conventional winch (not shown) located at the surface of the earth, is employed to'raise the device in the borehole in a cus-v tomary manner. In this -way the fluid sampler may be positioned so that a portion thereof in the vicinity of side rails 17 and 18 is adjacent the selected formation 12.

' In the vicinity of side rails 17 and 18, there is disposed a normally retracted pad or pack-off shoe 20 comprised of a sealing face 21 provided with the central insert 22 having upper and lower apertures 23 and 24, the functions of which will be described hereinafter. Sealing face 21 is peripherally connected to a generally ovalshaped, horizontally curved support ring 25 `and in the normally-retracted position of shoe 20, the central portion of face 21 containing insert 22 is spaced from a reference plane defined by the side portions of support Y ring 25 as disclosed in the copending application of Harry B. Boller filed March 25, 1954, bearing the Serial No. 418,650 (now Patent No. 2,821,256) and assigned to the same assignee as the present application.

vAs best seen in Fig. 2, a horizontally-curved driving plate 26 is Awelded or otherwise peripherally connected,

to support ring 25. It is provided with a central opening 27 through which a portion of insert 22 and a portion of gun block 2S may pass.

-A bore 29 extends through insert 22A and gun block 2S and is adapted to receive a projectile (not shown) and an appropriate propellant (not shown) for limpelling -thc projectile through the bore and out of opening 24 thereby to penetrate the formation under investigation. In addition, the projectile opens a normally-closed aperture which is connected to a -tube 30, in turn, connected to a sample-receiving chamber (not shown) in lower housing section 16. This chamber may be of any Well-known construction or may be of the type described in aforementioned patent to Chambers for obtaining a uniform, representative sample of formation uid.

Another -bore 31 extends from opening 23 in insert 22 and through gun yblock 28. Its forward 'end is normally blocked by a closure 32 and explosively-operated means (not shown) is positioned within bore 31. Thus, the bore may be opened to uid flow thereby to provide a fluid communication path between the front and rear surfaces of sealing face 21 and the seal made between the face and the sidewall of the borehole may be broken after a sample is obtained. l This type of release mechanism is disclosed in the copending application of Clyde C. Chivens and Roger Q. Fields, filed March 25, 1954, bearing the Serial No. 414,644 and assignedto the same assignee as the present application.

In order to displace the pack-off shoe 20 from a normally-retracted position adjacent to side rails 17 and 18, as shown in Fig. 1, to an extended or active position in engagement with the sidewall of the borehole, as shown in Fig. 2, there are provided hydraulic motors or drivers within a pair of housings 33 and 34 secured between side rails 17 and 18 in longitudinally spaced relation from one another. Housings 33 and 34 contain hydraulic cylinders 35 and 36 Whose axes are oriented perpendicularly to and lie in a plane passing through the longitudinal axis of housing sections and 16. The cylinders 35 and 36 receive pistons 39 and 40, respectively, which are mechanically coupled to driving plate 26 -in a manner to be described more fully hereinafter. A pair of similar cylinders 41 and 42 within the housings 33 and 34 are oriented so that their axes lie in the just-described plane, but face in directions opposite to cylinders 35 and 36. The cylinders 41 and 42 receive respective pistons 43 and 44 which are mechanically connected to a back-up pad or shoe 45 in a ma-nner to be evident from lthe discussion to follow.

The cylinders 35, 36, 41 and 42 are uidly connected by a conduit 46, and various extensions thereof, to a hydraulic pressure generator 47 disposed in upper housing section 15. Generator 47 may, for example, be of the type described in the aforementioned patent to Chambers for utilizing the pressure of the borehole fluid 14 to derive a hydraulic pressure for displacing the pistons 39, 40, 43 and 44 through their respective cylinders. Thus, the shoes and 45 may be driven in opposite direct-ions away from side rails 17, '18 ltoward theY sidewall of the borehole. Of course, any wellknown system may be employed to impart movement lto ythe driving plate 26 and the shoe 45. `For example, a motor-driven screw-type jack can be used. Each of a pair of tension springs 48 and 49 is connected at its extremities to adjacent end portions of driving plate 26 and .back-up shoe 45. They are arranged to bias the plate and the shoe toward one another and .thus before hydraulic pressure is applied to the cylinders the springs maintain the driving plane and the back-up shoe in normally-retracted positions as shown in Fig. 1.

Since the borehole may not always be of uniform diameter, in certain instances lit may exhibit a tilted appearance relative yto the cross-sectional representation 4 shown in Fig. 2. Obviously, if the faces of shoes 20 and 45 are maintained in substantially fixed-parallel relation to one another it may be diflicult to obtain a seal with the sidewall of the borehole. Accordingly, there is proivded a mechanical coupling embodying the present invention. Specifically, the pistons 39 and 40 are connected to driving plate 26 and the pistons 43 and 44 are connected to back-up shoe 45 in a manner permitting relative pivotal movement between the pistons and the members Iin a plane such as defined hereinbefore by the longitudinal axes of the several cylinders.

To this end, piston 39 is provided with an end 50 of convex, generally spherical contour and an axial hole 51 which receives a threaded part 52 of a screw 53. Screw 53 has a shank S4 of a larger diameter than hole S1 so that the screw may be tightened and thereby fixed -in position. Shank 54 passes through an opening 55 in driving plate 26 which loosely receives .the shank and the opening has a concave extension 56 of generally spherical shape, or conforming generally to the configuration of end 5t) of piston 39. A cylindrical, shallow recess 57 extending from the opposite surface of driving plate 26 constitutes a forward extension of opening 55 and receives head 58 which may be of conical configuration. The distance between cylinder end 50 and head 58 is greater than the distance between opposed wall portions of opening sections 56 and 57. It is thus evident that vthe connection just described has relatively movable portions which are pivotal in the aforedescribed longitudinal plane as Well as in a transverse, horizontal plane. In other words, this connection provides freedom of movement so that in effect, although the piston 39 and the driving plate 26 are mechanically connected for movement in a direction perpendicular to the longitudinal axis of housing sections 15 and 16, a slight relative movement is permitted in all other directions, ie., there are two degrees of freedom, to a limited extent.

The same general type of connection just described comprised of components 50-58 is provided at area 59 for mechanically coupling piston 40 and driving plate 26. However, opening 60 in plate 26 is enlarged in a longitudinal direction, i.e., it is of oval shape to permit relative displacement in a longitudinal direction between piston 40 and plate 26. At zone 61 a connection similar lto the one including components 50-58 mechanically couples back-up shoe 4S to piston 43. Longitudinally spaced from zone 61 is another zone 62 where shoe 45 is mechanically coupled to piston 44 by a connection like the one at zone 59 .including an oval shaped openmg.

The various control circuits for hydraulic generator 47, the propellants or explosives (not shown) in gun block 28 and various valves (not shown) are completed via insulated electrical conductors of cable 19. These circuits may be any conventional arrangement or may be ofthe specific type disclosed in the above-mentioned patent to Chambers.

In operation, the borehole apparatus including housing sections 15, 16 is lowered in borehole 10 by means of cable 19 to a position wherein insert 22 is adjacent the formation to be tested; in this example it is formation 12. This portion of an operating cycle is illustrated in Fig. l. Thereafter, hydraulic pressure generator 47 iS operated and hydraulic pressure is applied via conduit 46 to the cylinders 35, 36, 41, and 42 so that the pistons 39, 40, 43 and 44 are displaced. Accordingly, driving plate 26 and back-up shoe 45 are driven in opposition to the bias of springs 48 and 49 toward the sidewall of the borehole.

Since in the case illustrated in Fig. 2, boreholeV 10 has an enlarged section in the vicinity of formation 12 whose diameter increases with depth, initially the upper sections of shoes 20 and 4S engage the sidewall. By reason of the pivotal connections provided between the several pistons and the driving plate *26 and the back-up shoe 45,

although the pistons continue to move in essentially xed, transverse directions, the shoes are permitted to pivot relative to the pistons at their connection points. Thus the shoes may conform to the general outlines of the borehole. In other words, although movement of the upper ends of the shoes 20 and 45 is interrupted, the pivotal connections make it possible for the lower pistons 40 and 44 for the shoes 20 and 45 to move farther than the upper pistons 39 and 43. Consequently, although the longitudinal axis of housing sections 15, 16 remains essentially in alignment with the axis of borehole`10, the shoes 20 and 45 are permitted to tilt into engagement with the sidewall. Since-the axes of the pistons always remain fixed with respect to their respective cylinders, pivotal motion of the shoes is accompanied by changes in the linear distances between the ends of the pistons 39 and 40 and the pistons 43 and 44. Such changes are accommodated by oval-shaped opening 61 in plate 26 and the correspondingly oval-shaped opening in back-up shoe 45. By permitting the shoes to tilt, sealing face 21 may engage and conform very closely to a relative large section of sidewall to provide a very effective iluid seal between the sidewall of borehole and drilling fluid 14.

After the shoes are properly positioned, the bullet (not shown) in bore 29 is impelled out through opening 24 to penetrate formation 12` and to complete a uid connection between the formation and tube 30. Thus, lluid from the formation may flow into the sample-receiving chamber (not shown) in housing section 16 and after a given interval of time in which the chamber can be lled, it is closed and the device is ready to be brought to the surface.

Hydraulic pressure generator 47 may then be de-activated to reduce the hydraulic pressure in the several cyl-` inders. For example, the pressure may be brought to atmospheric pressure by the use of a suitable low pressure or dump chamber (not shown). Accordingly, the hydrostatic pressure of the drilling mud 14 acting on the pistons via the shoes 20 and 45, together with the bias of springs 48 and 49, displaces the shoes toward their re tracted positions.

In the event the close seal between sealing face 21 and sidewall of the borehole prevents the shoe 20 frombeing retracted, a release mechanism associated with bore 31 of insert 22 may be operated. This equalizes the pressure dierential between the two surfaces of sealing face 21 and the shoe may be retracted.

The fluid sampler thus may be withdrawn from borehole 10. At the surface, the sample-receiving chamber (not shown) can be removed from housing section and the sample therein may be measured and analyzed in any known manner.

It is therefore evident that by the use of pivotal mechanical connections between the pack-off shoe and back-up shoe 45 and their respective pistons, a good fluid seal between sidewall of the borehole and pack-off shoe may be obtained and samples of formation fluid may be eicently and reliably taken.

In the embodiment of the invention illustrated in Fig. 4, between the side rails that connect housing sections 15 and 16 there is disposed a cylinder housing 70 for cylinders 71 and 72. The axes of the cylinders 71 and 72 are disposed in a plane intercepting the longitudinal axis of housing sections 15 and 16 and are in spaced, parallel relation to one another. The cylinders receive pistons 73 and 74 whose free ends are rigidly connected to a driving plate 75 of a pack-oli shoe 76. A pivot pin or bolt 77 extends through the side rails and through cylinder housing 70 and is appropriately arranged in a known manner so that the cylinder housing 70 is pivotally movable relative to the longitudinal axis of housing sections 15 and 16 in the just described plane.

Supported above and below the cylinder housing 70 are cylinders 77 and 78, respectively, each of which receives one of pistons 79 and 80. The pistons 79 and 80 have individual back-up members 81 and 82.

The remainder of the apparatus may be of the same general type described hereinbefore in connection with Figs. 1 and 2, however, individual springs may be provided for retracting the shoe 76 and the back-up members 81 and 82.

When the apparatus of Fig. 4 is operated in a borehole 83 of non-uniform diameter, as shown in Fig. 4, it is evident that the back-up members 81 and 82 engage one section of the sidewall whereas the pack-off shoe 76 engages an opposite section. To accommodate an nclination of the sidewall due lto the non-uniform diameter of borehole 83, cylinder housing 70 tilts relative to the* longitudinal axes of housing sections 15, 16.

It is thus evident that by providing a mechanical coupling between the actuator contained by housing 70 and the support, permitting relative pivotal movement in a plane passing through the longitudinal axis of the support, the apparatus may be usefully employed in a borehole of non-uniform diameter and samples of formation iluid may be reliably obtained.

If desired, in either of the embodiments described herenbefore, instead of using one or more movable back-up members, an appropriately shaped pad may be supported in mechanically iixed relation to housing sections 15 and 16. In this case, only the pack-olf shoe is movable and one of the connections between the housing sections 15 and 16 and the actuator and between the actuator and the pack-oi shoe has portions which are pivotally movable relative to one another in a plane passing through the longitudinal axis of housing sections 15 and 16.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects, and therefore ,the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

lclaim:

vl. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a wall-engaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall of the borehole; actuating means for said wall-engaging member carried by said support; a rst connection for mechanically coupling said support to said actuating means, a second connection for mechanically coupling said actuating means to said wallengaging member, and an attaching means for one of said connections to permit tilting movement of said wallengaging member with respect to said longitudinal axis.

2. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a wall-engaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall of the borehole; actuating means for said wallengaging member carried by said support and including members movable relative to one another along an axis substantially fixed with respect to at least one of said members; iirst connection means for mechanically coupling said support to one of said members of said actuating means, second connection means for mechanically coupling the other of said members of said actuating means to said wall-engaging member, and pivotal attaching means for one of said connections to permit relative pivotal movement in a plane passing through said longitudinal axis.

3. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a 'wall-engaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall of the borehole; actuating means for said wallengaging member carried by said support; rst connection means for mechanically coupling said support to said actuating means, second connection means for mechanically coupling said actuating means to said wall-engaging member and pivotal attaching means on one of said connections for relative movement in substantially all planes passing through said longitudinal axis and intercepting said one connection, but essentially rigidly connected relative to the line of intersection of said planes.

4. Borehole apparatus comprising: a support adapted to be passed through a borehole and havin-g a longitudinal axis; a wall-engaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall ofthe borehole; actuating means for said wall-engaging member mounted to said support and including a pair of driven members spaced from one another in the direction of said longitudinal axis and movable in respective directions transverse to said longitudinal axis; and a pivotal connection mechanically coupling each of said driven members to a respective portion of said Wallengaging member.

5. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a walhengaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall of the borehole; actuating means for said wall-engaging member mounted to said 4support and including a pair of driven members spaced from one another in the direction of said longitudinal axis and movable in respective xed directions transverse to said longitudinal axis; and a pair of connections mechanically coup-ling respective ones of said driven members to respective portions of said Wall-engaging member, each of said connections having portions pivotally movable with respect to one another in a plane dened by said longitudinal axis and said directions and said movable portions of at least one of connections being movable relative to one another in a direction parallel to said longitudinal axis.

6. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a pair of Wall-engaging members carried by said support, and movable from retracted positions adjacent said support in opposite directions toward an active position in engagement with. respective sidewall portions of the borehole; actuating means for said wall-engaging members mounted to said support and including first and second pairs of driven members, the members of each of said pairs being spaced from one another in the direction of said longitudinal axis and movable in parallel directions transverse to said longitudinal axis; and first and second pairs of pivotal connections, each of said pivotal connections in said first pair of pivotal connections mechanically coupling one of said first pair of driven members to a respective portion of one of said Wall-engaging members, and each of said pivotal connections in said second pair of pivotal connections mechanically coupling one of said second pair of driven members to a respective portion of the other of said wall-engaging members.

7. Borehole apparatus comprising: a support adapted to be passed through a borehole and having a longitudinal axis; a wall-engaging member carried by said support and movable from a retracted position adjacent said support toward an active position in engagement with the sidewall of the borehole and having a pair of openings spaced from one another in the direction of said longitudinal axis; actuating means for said wall-engaging member mounted to lsaid support and including a pair of driven members spaced from one another in the direction of said longitudinal axis and movable in respective direc tions transverse to said longitudinal axis; and a pair of pivotal connections, each of said pivotal connections mechanically coupling one of said driven members to a respective portion of said wall-engaging member and including an extension of said one driven member loosely received by said opening and having a head portion larger than the associated opening.

8. Borehole apparatus according to claim 7 wherein one of said openings is elongated along a line parallel to said `longitudinal axis.

References Cited in the le of this patent UNITED STATES PATENTS 2,690,224 Roberts Sept. 28, 1954 Chambers Apr. 6, 1954` 

